Silicon carbon composite particles

Abstract

Silicon carbon composite particles and anode materials for use within lithium-ion batteries utilizing the silicon carbon composite particles. Where the silicon carbon composite particles have an alkali metal or alkaline earth metal concentration of 0.05 to 10 wt% and a pH > 7.5.

What is claimed is: 
     
         1 - 14 . (canceled) 
     
     
         15 . Silicon carbon composite particles, comprising:
 a) an alkali metal or alkaline earth metal concentration of 0.05 to 10 wt%; and   b) a pH > 7.5.   
     
     
         16 . The silicon carbon composite particles of  claim 15 , wherein the silicon carbon composite particles have a volume-weighted particle size distribution with diameter percentiles d 50  of 0.5 to 20 µm. 
     
     
         17 . The silicon carbon composite particles of  claim 15 , wherein the silicon carbon composite particles have at least 30 wt% of silicon obtained by silicon infiltration. 
     
     
         18 . The silicon carbon composite particles of  claim 15 , wherein in pores and on the outer surface of the silicon carbon composite particles silicon is present in the form of layers, or in the form of layers formed from silicon particles, having a thickness of at most 1 µm. 
     
     
         19 . The silicon carbon composite particles of  claim 15 , wherein the silicon carbon composite particles have a specific BET surface area of at most 100 m 2 /g. 
     
     
         20 . The silicon carbon composite particles of  claim 17 , wherein the silicon carbon composite particles have a pore volume P which is at least 100 vol%, based on the volume of the silicon obtained from silicon infiltration in the silicon carbon composite particles, the pore volume P of the silicon carbon composite particles resulting from the sum total of gas-accessible and gas-inaccessible pore volume. 
     
     
         21 . The silicon carbon composite particles of  claim 15 , wherein the silicon carbon composite particles are used in an anode material of a lithium-ion battery. 
     
     
         22 . A process for producing the silicon carbon composite particles, comprising:
 providing silicon carbon composite particles having an alkali metal or alkaline earth metal concentration of 0.05 to 10 wt% and a pH > 7.5 by silicon infiltration from silicon precursors which are selected from silicon precursors which are liquid or gaseous at 20° C. and 1013 mbar, in the presence of porous carbon particles, wherein the porous carbon particles, by treatment with a basic alkali metal or alkaline earth metal compound in a molar ratio of 100:1 to 5:1, based on the carbon present in the porous carbon particles, have an alkali metal or alkaline earth metal concentration of 0.1 to 20 wt% and a pH of > 7.5.   
     
     
         23 . The process of  claim 22 , wherein the silicon infiltration takes place in a reactor selected from fluidized bed reactors, rotary tube furnaces arranged horizontally through vertically, open or closed fixed-bed reactors, and pressure reactors. 
     
     
         24 . The process of  claim 22 , wherein silicon infiltration is carried out at 280 to 900° C. 
     
     
         25 . The process of  claim 22 , wherein the silicon carbon composite particles are produced by silicon infiltration from silanes selected from monosilane and chlorine-containing silanes. 
     
     
         26 . An anode material for a lithium-ion battery, comprising:
 wherein the anode material comprises the silicon carbon composite particles having an alkali metal or alkaline earth metal concentration of 0.05 to 10 wt% and a pH > 7.5.   
     
     
         27 . The anode material for a lithium-ion battery of  claim 26 , wherein the anode material is coated on a current collector.